The authors reviewed the passenger lymphocyte syndrome (PLS) that has appeared after transplantation. The definition, mechanism, serological, clinical features, and treatment for PLS after solid organ transplantation, especially liver transplantation, are described. The PLS refers to the clinical phenomenon of alloimmune hemolysis resulting from the adoptive transfer of viable lymphocytes from donor during solid organ or hematopoietic stem cell transplant. Sometimes, it is very severe and may cause “unexplained” hemolysis during the postoperative period. The authors reviewed literature about the PLS in liver transplantation.

Previous studies have suggested that the lower limb arteriosclerosis obliterans (LASO) could be improved by autologous transplantation of either bone marrow mononuclear cells (BM-MNC) or G-CSF-mobilized peripheral blood mononuclear cells (M-PBMNC). However, the number of patients observed was very limited, and little information is available regarding comparison. The present randomised trial was designed to assess which is the better option. One hundred fifty patients with LASO were randomised to either group A (76 cases implanted with M-PBMNC) or group B (74 cases implanted with BM-MNC), and followed up for 12 weeks. Primary outcomes were safety and efficacy of treatment, based on ankle-brachial index (ABI) and rest pain, and analysis was per protocol. Significant improvement of the main clinical index was observed in both groups after transplantation. No transplantation-related complication was observed in either group. Comparative analysis revealed that at 12 weeks after cell implantation, improvement of ABI (difference 0.06 +/- 0.01; p < 0.0001), skin temperature (difference 0.55 +/- 0.25; p = 0.028), and rest pain (difference -0.57 +/- -0.15;p < 0.0001) was significantly better in groupA patients than group B patients. However, there was no significant difference between two groups for pain-free walking distance, transcutaneous oxygen pressure, ulcers, and rate of lower limb amputation. Autologous transplantation of either M-PBMNC or BM-MNC significantly promotes improvement of limb ischaemia in patients with LASO. Comparative analysis indicated that M-PBMNC should be more practical in comparison with BM-MNC in the treatment of LASO.

Regulatory T (Treg) cells may participate in mediating a suppressive microenvironment that blunts successful anti-tumor immunotherapy. Recent studies show that CD8+ Treg cells might impede effective immune responses to established tumors. However, there is limited research regarding CD8+ Treg cells in ovarian cancer (OC) patients. Here, we investigated CD8+ Treg cells in OC patients and their in vitro induction. The immunohistochemistry of tumor-infiltrating lymphocytes revealed a significant correlation between the intratumoral CD8+ T cells and the forkhead box p3 (Foxp3)+ cells in the intraepithelial and stromal areas of advanced OC tissues. We examined the expression of Treg markers in CD8+ T cells from the peripheral blood and fresh tumor tissues of OC patients using flow cytometry. Our results indicated an increase in the CD8+ Treg cell subsets of OC patients compared with those in patients with benign ovarian tumors and healthy controls, including an increased expression of CD25, cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), and Foxp3 and decreased CD28 expression. To demonstrate whether the tumor microenvironment could convert CD8+ effector T cells into suppressor cells, we used an in vitro transwell culturing system. Compared with the CD8+ T cells cultured alone, the CD8+ Treg cells induced in vitro by coculture with SK-OV-3/A2780 showed increased CTLA-4 and Foxp3 expression and decreased CD28 expression. In addition, the in vitro-induced CD8+ Treg cells inhibited naïve CD4+ T-cell proliferation, which was partially mediated through TGF-β1 and IFN-γ. Our study suggests that CD8+ Treg cells were increased in OC patients and could be induced in vitro, which may be the way that tumors limit antitumor immunity and evade immune surveillance.

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